So polygonal pathfinding? Or am I misreading something? This would be very nice, and the pathfinding would come in handy in my Flight Sim... if I ever get it working.

3D mesh pathfinding if you will, meaning instead of generating a 2D grid map for pathfinding it will relate its pathfinding information according to the geometry.
I am unsure how it would relate and help you using 3D pathfinding in a flight sim however.(as airplanes doesn't move after information on ground, they avoid it in which case it isn't really pathfinding you need, but obstacle avoidance if it is AI as players normally wouldn't crash their planes mindlessly into the ground)

I did some experimenting with integrating Recast/Detour into EE a while back as well. See screen shots below. You can't see it in the shots, but there are soldiers walking around the island. The agents can walk over the bridge and up the stairs. It worked quite well. The only thing missing is the temporary obstacles, which I believe is being worked on at the moment.

I'm really looking forward to it becoming a core part of EE, especially with temporary obstacle support, so a building can be placed on the terrain and then removed, having it affect the nav mesh.